Compact Four-Port Dual-Sense Circularly Polarized Stack-Up Patch Antenna for UHF/MW-RFID MIMO System

Table 2

Performance comparison with other proposed dual-band multiport CP antenna systems.

Ref.	Size [λ^3]	Ports and polarization	Bands (GHz)	IBW (%)	ARBW (%)	Isolation (dB)	Gain [dBic]	ECC
[9]	0.6 × 0.6 × 0.09	One port	0.915	2.6	5.3	—	2.9	—
		Same sense	2.45	2	2		6.1
[10]	0.5 × 0.5 × 0.04	One port	0.92	4.8	4.8	—	6.5	—
		Dual-sense	2.45	16.7	16.7		7
[15]	0.6 × 0.6 × 0.05	Two ports	0.915	2.8	2.8	25	−0.6	—
		Same sense	2.45	3.2	0.8	20	1.2
[16]	0.7 × 0.7 × 0.1	Two ports	0.92	3.4	4.4	10	6.6	—
		Dual-sense	2.45	7	8.2	10	7.9
[21]	0.9 × 0.6 × 0.01	Two ports	2.45	20	—	20	—	0.5
		Dual-sense	3.5	18.8	5	16
			5.3	15.2	—	18
[22]	0.8 × 0.2 × 0.01	Two ports	2.45	36	36	15	6	0.0001
		Dual-sense	5.8	17	17	20	2.6	0.0001
[23]	1.1 × 0.5 × 0.11	Four ports	2.45	12.7	3.5	25	7.3	0.03
		Dual-sense	5.8	5.1	6.2	30	7.3	0.03
This work	0.6 × 0.6 × 0.07	Four ports	0.915	10.9	14.2	20	4.1	0.01
		Dual-sense	2.45	9.4	7.4	25	7.4	0.01

The radiating elements radiate two orthogonal LP fields at the WLAN band and CP field in the range 3.31–3.48 GHz (within the WiMAX band). Antenna performance here indicated refers to the WiMAX band, where a CP MIMO system is obtained.